16alpha-lower alkyl pregnane and choleno derivatives



Patented Dec. 11, 1962 This application is a continuation-in-part of our copending application Serial No. 754,181, filed August 11, 1958, now abandoned.

This invention is concerned generally with steroid compounds and with novel processes of preparing the same, more particularly, it relates to l6u-alkyl-1l-oxygenated steroids of the pregnane series unsaturated in ring A.

The 16a-alky1 steroids produced in accordance with this invention possess extremely high anti-inflammatory activity, considerably greater than that of the parent steroids and are especially effective for the treatment of arthritis and related diseases since they can be administered for their cortisone-like action in extremely low dosage thereby minimizing undesired side effects.

In preparing these active compounds, the starting material utilized may be 3/3-acyloxy-16x-alkyl-5(6)-pregnen-ZO-one which maybe represented as follows:

' i aI U/W where R is alkyl, R is acyloxy and X is halogen.

It has been found that 3,8-acyloxy-16a-alkyl-5,6-dihalopregnane-ZO-one may be caused to react with dialkyl oxalate such as dimethyl oxalate, diethyl oxalate, etc. to form the alkyl ester of l6a-alkyl-5,6-dihalo-3B-hydroxy- 20-oxo-2l-pregnaneglyoxylic acid which has the following structural tormula- 97 H a l-a e a c on G2 Gite a G3 a i =1 0 Cm a wherein R, R and X are as above.

The 3 [3,23-diacy1oxy- 1 6OC-alkyl-5,6-dlha10-2 l-normethyl- 17(20),22-choladieno-24(20)-lactone can be reacted with a peracid such as perbenzoic acid to form 3fi,23-diacyloxy 16a-alkyl5,6-dihalo-2l-normethyl 17(20) oxido- 22-cholano-24(20)lactone which has the following structural formula:

wherein R, R and X are as above.

When 35,23-diacyloxy-l6e-alkyl-5 6-dihalo-21 normethyl- 17(20)-oxido-22-cholano-24(20)-lactone is reacted with base, the epoxy ring is broken and there is obtained 16a-alkyl-S,6-dihalo-3p,l7a-dihydroxypregnan 20-one which has the following structural formula:

Halogenation of 16ot-alkyl-5,6-dihalo-3;3,17a-dihydroxypregnan-ZO-one results in the formation of l6a-alkyl-5,6, 21-trihalo-3fi,17a-dihydroxy-pregnan-ZO-one which may be represented as follows:

wherein R and X are as above.

Treatment of l6oc-alkyl-5,6,2l-trihalo-3p,l7a-dihydroxypregnan-ZO-one with an acylating agent results in the formation of 16a-alkyl-5,6-diha1o-3 3,l7a,2l-trihydroxypregnan-20-one 2l-acylate which may be indicated as follows:

wherein R, R and X are as above.

When l6a-alkyl-5 ,6-dihalo-3 ,8, 17,2 1-trihydroxy-pregnamZO-one 21-acylate is oxidized with an oxygenating agent such as chromium trioxide there is obtained 16a- 4 alkyl-5,6-dihalo-17a,21-dihydroxy-pregnan-3,ZO-dione 21- acylate which may be indicated as follows:

wherein R, R and X are as above.

Chromous halide when reacted with 16ot-alkyl-5,6-dihalo-17u,21-dihydroxy-pregnan-3,ZO-dione Zl-acylate removes halogen atoms at positions 5 and 6 and results in the 16ix-alkyl-17a,21-dihydroxy-4-pregnene-3,20-dione 21- acylate which has the following structural formula:

wherein R, and R are as above.

The 16a-alky1-17a,21-dihydroxy-4-pregnene-3,ZO-dione 2l-acylate can be reacted with selenium dioxide to eflect ring A dehydrogenation, thereby forming the 16a-alkyl 17oz 21-dihydroxy-l,4-pregnadiene-3,20-dione 21 acylate compound. This selenium dioxide dehydrogenation procedure is carried out by reacting l6a-alkyl-17a,2l-dihyd-roxy-4 pregnene-3,20-dione compound and selenium dioxide in the presence of an organic solvent such as dioxane and an alcohol solvent such as t-butanol and heating the mixture at an elevated temperature. The reaction a mixture is filtered, thereby removing metallic selenium and the filtered solution is evaporated to dryness in vacuo to give the desired 16a-alkyl-17u,21-.dihydroxy-1,4-pregnadiene-3,20-dione 21-acylate compound.

The l6ot-alkyl-170:,21-d-ihydroxy-1,4-pregnadiene 3,20- dione ZI-acylate can be subjected to a microbial procedure to introduce an hydroxy group in the ll-position, thus forming 16a-alkyl-l1,17a,2l-trihydroxy-1,4-pregnadiene- 3,20-dione 2l-acylate which possesses extremely high anti-inflammatory activity.

The hydroxy group at ll-position can be introduced by subjecting 16u-alkyl-17a,2l-dihydroxy-l,4-pregnadiene-3, 20-dione Zl-acylate to an oxygenating strain of the organism Curvularia lunata (Northern Regional Research Laboratories, No. 2434) in a suitable nutrient medium.

In all of the previously described reactions, R has been designated as alkyl, and is intended to include the lower alkyl groups such as methyl, ethyl and propyl, or aryl alkyl. R has been indicated as acyloxy. The acyloxy groups that may be employed in these reactions include lower hydrocarbon carbonyloxy esters such as benzoate, lower alkanoates such as acetoxy, and propionoxy, X is halogen and is intended to include bromo, chloro, fluoro and iodo. it will be evident to those skilled in the art that other groups may be substituted for those recited here and these definitions are intended only as some indication of the operable class of compounds intended.

The following experimental part illustrates in detail some of the compounds which constitute this invention and methods for their production. However, this invention is not to be construed as limited thereby in spirit or aoeaaas in scope since it will be apparent to those skilled in the art that many modifications in materials and methods may be made without departing from the invention.

EXAMPLE 1 Preparation of Sfi-Acetxy-5,6-Dichl0ro-J6a Methyl-ZO-Pregnanone Chlorine gas was slowly bubbled into 40 ml. of benzene containing .21 ml. of pyridine. Simultaneously, a solution of 6.0 g, of 3,8-acetoxy-16a-methyl-5(6)-pregnen-20- one in .40 ml. of benzene containing .21 ml. of pyridine was added to the chlorine-benzene solution. The rate of addition of the steroid solution was adjusted so that a slight excess of chlorine was present. The addition of the steroid required 25 minutes. The reaction mixture was poured into sodium thiosulfate solution to destroy the excess chlorine. The benzene solution was washed with 5% hydrochloric acid, sodium bicarbonate solution and water. The benzene solution was then dried and concentrated to dryness. The residue was dissolved in hot acetone treated with charcoal and filtered. The filtrate was evaporated on the steam bath until crystallization started. The mixture Was cooled and filtered to yield 3B-acetoxy-5,6-dichloro-16a-methyl-20-pregnanone which melted at 195l98 C.

The 36-acetoxy-16wmethyl-5(6)-pregnen-20-one used as a starting material in this example is prepared as follows:

A solution of g. of methyl iodide in 40 ml. of ether is added to 1.73 g. of magnesium in 50 ml. of ether. To

the resulting 90 ml. of ethereal solution of methyl magnesium iodide, maintained under a nitrogen atmosphere was added 50 ml. of ether followed by the addition of .64 g. of cuprous chloride. The mixture was stirred vigorously for 1.5 hours at C. and then refluxed for /2 hour. At the end of this time the yellow cuprous chloride was converted to a fine black insoluble powder. A solution of 16.4 g. of 3-acetoxy-5(6), 16-pregnadiene-20-one in 500 ml. of absolute ether, was added over a period of 1 hour. The mixture was then refluxed for 6 hours with stirring. The methyl magnesium iodide complex and excess methyl magnesium iodide was decomposed by the careful addition of 150ml. of 10% sulfuric acid. The mixture was then filtered through diatomaceous earth and transferred to a separatory funnel. layer was separated and back extracted with 200 ml. of ethyl acetate. The ethyl acetate was combined with the ether layer and washed successively with water, 5% sodium sulfite solution, water, 10% sodium bicarbonate solution and finally with water. dried and concentrated in vacuo until crystallization started. The ethyl acetate solution was then distilled at atmospheric pressure until crystallization of 3,8-hydroxyl6ot-methyl-5(6)-pregnen-20-one began. The solution was cooled to 10 C. and filtered. Wt. 10.89 g. 182188 C. Recrystallization from ethyl acetate raises the melting point to 189-191 C.

A mixture of 50.0 g. of 3t3-hydroxy-l6a-methyl-5(6)- pregnemZO-one in 200 ml. of acetic anhydride and 200 ml. of pyridine was allowed to stand for 18 hours at 20 C. The mixture was concentrated to dryness and the residue dissolved in benzene. The benzene solution was washed with sulfuric acid, saturated sodium bicarbonate solution and water. The benzene solution was dried and concentrated to dryness. Petroleum ether was added to induce crystallization. The Sfi-acetoxy-16u-methy1-5(6)- pregnen-ZO-one was filtered and dried. Wt. 50.3 g. M.P. 181-185 C.

EXAMPLE 2 Preparation of the Ethyl Ester of 5,6-Dichl0r0-3-Hydr0xy- 1 6a-Met]zyl-20 Ox0-2I-Prgnaneglyoxylic Acid Sodium methoxide was prepared by adding ml. of methanol to 3.18 g. of clean sodium in a 250 ml. roundbottom flask. To the mixture was added 100 m1. of dry The aqueous acetic The organic solution was toluene and the mixture was distilled slowly until the boiling point of the distillate was 110 C. Diethyl oxalate (24.6 grams) was then added slowly to the cooled sodium methoxide solution maintaining the temperature between 20-25 C. Then 11.8 grams of 3fl-acetoxy-5,6-dichlorol6e-methyl-pregnane-ZO-one was added and the yellow solution stirred for 18 hours.

The mixture was poured slowly with stirring into 250 ml. of ether-petroleum ether (1:1) to precipitate the ethyl ester of 5,6-dichloro-3B-hydroxy-l6a-methyl-20-oxo-21- pregnancglyoxylic acid. Ethanol ml.) was then added to the ethyl ester of 5,6-dichloro-3;3-hydroxy-16amethyl-20-oxo-2l-pregnaneglyoxylic acid and the mixture acidified by addition of 2.5 N hydrochloric acid. To this mixture was added 250 ml. of water and 250 ml. of benzene and stirred for 10 minutes. The benzene layer was separated and washed with water until neutral. The benzene solution was dried and concentrated in vacuo to yield 16.3 g. of the ethyl ester of 5,6-dichloro-35-hydroxy-16amethyl-ZO-oxo-Z1-pregnaneglyoxylic acid. U.V./max. 2920, E% 135.

EXAMPLE 3 Preparation 0 f 5 ,6 -Dt'clz [01-0-3 5-H ydroxy-I 6 Ot-M etlz yl-20- 0.1;0-2 1 -Preg. zaizeglyoxylic Acid To 16.3 grams of the ethyl ester of 5,6-dichloro-3fi-hydroxy-16ot-methyl-20-oxo-2l-pregnaneglyoxylic acid was added 250 ml. of methanol and then over a period of 20 minutes 250 ml. of .5 N sodium hydroxide was added. The mixture was stirred for 5 hours and then rapidly heated to 70 C. and held at 70 C. for five minutes. The clear solution was cooled rapidly to 25 C. and acidified with 2.5 N hydrochloric acid. The precipitate was collected and washed thoroughly with water. The crude 5,6 dichloro-3B-hydroxy 16o: methyl-20-oxo-21- pregnaneglyoxylic acid was slurried with 100 ml. of acetonitrile, filtered and dried. Wt. 10.02 grams, MP. 209- 211 C. U.V./max. 2910, E% 208.

EXAMPLE 4 Preparation of 3 {3,23 -Diacet0xy-5 ,6-Dich Zora-1 6 a-M ethy l- 21 -N0rmethy l-l 7 (2O ,22-Clzoladien0-24 (2O -Lact0ne Acetic anhydride (82 ml.) was added to 2.2 grams of 5,6 dichloro-BB-hydroxy-l6a-methyl 20-oxo-2l-pregnaneglyoxylic acid. To this suspension was added 300 mg. of dinitrobenzene sulfonic acid. The mixture was stirred for 2 hours and 300 mg. of potassium acetate was added and the solution concentrated in vacuo below 50 C. to dryness. The 35,2S-diacetoxy-5,6-dichloro-16ot-methyl- 2l-normethyl17(20),22-choladieno-24(20)-lactone was dissolved in 250 ml. of benzene and washed successively with two portions of 100 ml. of cold 2.5 sodium hydroxide and two portions of 100 cc. of water. The benzene solution was dried and concentrated to dryness to yield an orange-red oil which yielded light tan crystals on trituration with ethanol. The 36,23-diacetoxy-5,d-dichloro-l61xmethyl-2l-normethyl-l7(20),22-choladieno-24(20) lactone weighed 8.6 g. U.V./max. 2990, 15% 423.

EXAMPLE 5 Preparation of 313,23-Diacct0xy-5 ,6-D ichloro-I 6a-M ethyl- 21-N0rmetlzyl-]7(20) -Oxido-22-Ch0len0-24(20) Lac- Zone A solution of 8.61 grams of 3B,23-diacetoxy-5,6-dichloro-l6ot-methyl-21-normethyl 17(20),22 choladieno-24 (20)-lactone was dissolved in 82 ml. of .55 M perbenzoic acid in benzene. The solution was allowed to stand at room temperature'for 5 days. The benzene solution was then washed successively with 5% sodium bisulfite solution, saturated sodium bicarbonate solution, and finally with saturated sodium chloride solution. The benzene solution was dried and concentrated to dryness to yield an oil which crystallized on addition of 50 ml. of petroleum ether. Filtration yielded 8.68 grams of 313,23-diacetoxy- 5,6-dichloro-16ot-methyl-21-normethyl 17(20) oxido- 22-choleno-24(20)-lactone TIN/max. 2280, 13% 194.

EXAMPLE 6 Preparation of 5 ,6-Dicltior-3 [3,1 7a-Dihydr0xy-16a- M etlzy l-Pregnan-2 O-One tion from methanol raised the melting point to 215-2l6 C. dec.

EXAMPLE 7 Preparation 0 f 21 -B r0m0-5 ,6 -D ich Zora-3 6,1 7a-Dihydr0xy- 1 6 OL-M ethy lPregnan-2 O-One To a solution of .207 gram of 5,6-dichloro-3fi,l7adihydroxy-l6a-methyl-pregnan-20-one in ml. of chloroform containing .01 ml. of methanol was added over a period of 1 hour, 1.56 ml. of .352 M bromine in chloroform solution. The chloroform solution was poured into ether and washed successively with saturated sodium bicarbonate solution and water. The chloroform-ether solu tion was dried and concentrated to yield an oil which crystallized on standing. This crystalline material, namely, 2l-bromo 5,6 dichloro-35,l7a-dihydroxy-16amethyl-pregnan-ZO-one was recrystallized from benzenepetroleum ether. MI. 190194 C.

EXAMPLE 8 Preparation of 5,6Dichl0r0-3t-3,1 70,21 -Triirydr0xy-1 6 c;- Methy l-Pregnan-ZO-One 21 -A cetate A mixture of .305 gram of 21-bromo-5,6-dichloro-3fi, 17ot-dihydroxy-l6a-methyl-pregnan-20-one; .294 gram of potassium acetate; .233 gram of potassium iodide; .001. ml. of acetic acid in 6 ml. of acetone was refluxed with stirring for 18 hours. The mixture was diluted with Water and filtered. The cake was dissolved in ethyl acetate and the ethyl acetate solution was Washed with water, dried and concentrated to dryness. The crystalline residue of 5,6-dichloro-3/3,17ot,21-trihydroxy-16ot-methylpregnan-ZO-one 21-acetate was crystallized from benzenehexane mixture, and melted at 192-194 C. Paper chromatography of the 5,6-dichloro-3B,l7tx,2l-trihydroxy-l60tmethyl-pregnen-ZS-o-ne ill-acetate gave a single spot (Rf .85) in the benzcne-formamide system as detected with blue tetrazolium and also phosphoric acid.

EXAMPLE 9 Preparation of 5 ,6 -Dich lore-1 70:,21 -Dihydr0xy-1 6 06- M ethyl-Pregnan-3 ,ZO-Dione 21 -Acetate A solution of .100 grarn of 5,6-dichloro-3,8,l7ot,2l-trihydroxy-16a-methyl-pregnan-ZO-One 21-acetate in 2 ml. of acetic acid containing .2 m1. of Water was cooled to 5 C. A solution of 22.7 mg. of chromium trioxide in .02 ml. water and .25 ml. of acetic acid was added dropwise to the solution, .012 ml. of concentrated sulfuric acid was then added and the temperature of the reaction maintained at 5 C. for 1 hour. The excess chromium trioxide was reduced with .02 ml. methanol and the mixture diluted with 8 ml. of water. The precipitate, containing 5,6 dichloro-l7a,21-dihydroxy-16a-methyl-pregnan-3,20-dione 2l-acetate was filtered, washed thoroughly with water and dried in vacuo at room temperature.

8 EXAMPLE 10 Preparation of l 7a,21-Dihydr0xy-16ot-Methyl-4-Pregnerte 3,20Di0ne ZJ-Acetate An acetone solution of chromous chloride prepared from .5 gram of chromic chloride was added to .10 gram of 5,6 dichloro-17ot,2l-dihydroxy-16ot-methyl-pregnan-3, ZO-dione Zl-acetate and refluxed for 5 minutes. The acetone was partially evaporated and then diluted with water. The precipitate, a mixture of the 4 and 5 pregnenes, was filtered, washed thoroughly with water and dried in vacuo at room temperature. The product was then dissolved in 4 ml. of acetone and the A double bond completely isomerized to A position by refluxing with .09 ml. of l N sulfuric acid in acetone. Acetone was distilled until crystallization started. The solution was cooled and filtered to yield 17u,21-dihydroxy-l6a-methyl- 4-pregnene-3,20-dione 21-acetate. MP. l62l64 C. U.V./max. 2400, E% :400.

Analysis.Calculated for C 4 I-l O C, 71.61; H, 8.52. Found: C, 71.56; H, 8.41.

EXAMPLE 11 Preparation of 1 704,21-Dihydr0xy-16a-Methyl-L4-Pregnadiene-3,20-Di0ne 21 -Acetate A suspension of 5 grams of 17a,21-dihydroxy-16amethyl-4-pregnene-3,20-dione 2l-acetate in 190 ml. of t-amyl alcohol, 6 grams of Se0 and 6 grams of mercuric oxide is refluxed for 17 hours. The solution is filtered from the metallic suspension and evaporated to an oil which is then dissolved in ethyl acetate. The ethyl acetate solution is washed with aqueous sodium bicarbonate and then with water until neutral and dried. Thesolvent is evaporated from the dried solution to give an oil which is dissolved in benzene and adsorbed from this solvent on acid-washed alumina. The adsorbate is eluted with ether petroleum ether and then with mixtures of ether and chloroform. The eluates are evaporated to dryness and the residual mixture recrystallized from ethyl acetate'ether to give 17ct,2l-dihydroxy-l6a-methyl-1,4-pregnadiene-3, 20-dione 21-acetate.

EXAMPLE 12 Preparation of 115,170,21-Trihydr0xy-16ot-Methyl-L4- Pregnadiene-S,ZO-Dione ZZ-Acctate A medium is prepared having the following composi-' tion:

Glucose g 20 An enzymatic lactoalbumen digest (Edamin) g 20 Cornsteep liquor ml 5 Water to make 1 liter.

This medium is distributed in ml. portions in appropriate vessels. The pH of the medium is adjusted to 6.5 with l M potassium hydroxide and sterilized at 120 C. for 12 minutes.

The medium in each vessel is then inoculated with a heavy aqueous suspension of spores of a strain of Curvalaria lttnata (Northern Regional Research Laboratory No. 2434) and the inoculated media are maintained at an incubation of 28 C. for 48 hours on a rotary shaking machine.

Ten mg. of 17ot,2l-dihydroxy-l6a-methyI-L4-pregnadiene-3,20-dione 21-acetate is added to each vessel from a dimethyl-formamide solution mg./ml.). The transformation is allowed to go for an additional 24 hours under conditions identical to the growth phase. The whole broth is then extracted 3 times with equal volumes of ethyl acetate, the extracts combined and finally concentrated. The 1lfi,1706,21-ll'lhYdlOXY-16OL-I'l'lfithYl-1, 4-pr-egnadiene-3,ZO-dione 21-acetate is filtered oil.

The l1B,l7a,21-trihydroxy 161x methyl-1,4 pregnadiene-3,20-dione 21-acetate thus obtained possesses high anti-inflammatory activity.

Various changes and modifications may be made in the present invention, certain preferred embodiments of which are herein disclosed, without departing from the scope thereof; to the extent that these changes and modifications are within the scope of the appended claims, they are to be considered a part of this invention.

What is claimed is:

1. Ethyl ester of 5,6-dichloro-3B-hydroxy-1fiat-methyl- 20-oxo-2l-pregnaneglyoxylic acid.

2. l6a-lower alkyl-5,6-dichloro 3/8-hydroxy-20 oxo- ZI-pregnaneglyoxylic acid.

3. 5,6-dichloro-3/i-hydroxy- 16a-methyl 20-oxo 21- pregnaneglyoxylic acid.

4. 35,23-diacetoxy-5,6-dichloro-16a-methyl 21 normethyl-17(20) ,22-choladieno-24(20) -lactone.

5. 3fl,23-diacetoXy-5,6-dichloro 16a-methyl 2l-n0rmethyl 1 7 20) -oXido-22-choleno-24 20 -lactone.

6. The process which comprises reacting 3/i-lower acyloXy-16a-lower alkyl-5,6-dichloro-pregnan-20-one with a lower dialkyl oxalate to form the lower alkyl ester of l6a-lower alkyl-5,6 dichloro 3fl-hydr0xy 20 Xo-21- pregnaneglyoxylic acid.

7. The process which comprises reacting the lower alkyl ester of 16a-lower alkyl-5,6-dichloro-3B-hydroxy-20- oxo-2l-pregnaneglyoxylic acid with an alkali metal hydroxide to form 16ix-1ower alkyl-5,6-dichloro-3-hydroxy- 20-oXo-2l-pregnaneglyoxylic acid.

8. The process which comprises reacting 1611- lower alkyl-5,6-dichlor0-3fi hydroxy-ZO oxo-21-pregnaneglyoxylic acid with dinitrobenzene sulfonic acid and lower acyl anhydride to form 35,23-lower diacyloxy-l6a-lower alkyl-5,6-dichloro-2l normethyl 17(20) -22-choladieno- 24(20)-lactone.

9. The process which comprises reacting 35,23-lower diacyloxy-l6u-lower alkyl-5,6-dichloro-21-normethyl-17- (20),22-choladieno-24(20)-lactone with a peracid to form 3,8,23-lower diacyloxy-16u-lower alkyl-5,6-dichloro-21- normethyl- 1 7 (20 -oXido-22-choleno-24 (20 -lactone.

10. The process which comprises reacting 3,8,23-lower diHCYIOXY-IGa-IOWSI alkyl-5,6 dichloro-Z1-normethyl-17- (20)-oxido-22-choleno-24(20)-lactone with base to form 16a-lower alkyl-5,6-dichloro 3fi,17a-dihydroXy-pregnan- 20-one.

11. Lower alkyl ester of 16a-lower alkyl-5,6-dichloro- 3 B-hydroxy-ZO-oxo-Zl-pregnaneglyoxylic acid.

12. 35,23-1ower diacyloxy-l6u-lower alkyl-5,6-dichloro- 2l-r1ormethy1-l 7 (20) ,22-choladieno-24 (20) -lact0ne.

13. 35,23-lower diacyloxy-16a-lower alkyl-5,6-dichloro 21-norrnethyl-1'7 (20) -oXido-22-choleno-24(20) -lactone.

References Cited in the file of this patent UNITED STATES PATENTS 

2. 16A-LOWER ALKYL - 5,6 - DICHLORO-3-B-HYDROXY-20-OXO21-PREGNANEGLYOXYLIC ACID. 